Two Step Annealing of Iridium Thin Films prepared by Plasma-Enhanced Atomic Layer Deposition

摘要

Plasma-enhanced atomic layer deposition of iridium thin film was investigated using (ethylcyclopentadienyl)(1,5-cyclooctadiene) iridium and ammonia plasma. The deposited Ir thin films had smooth surface and (111) preferred orientation due to atomic rearrangement by high energy of ammonia plasma. As a capacitor electrode material in dynamic random access memory applications, Ir thin films showed excellent thermal and morphological stability in ambient oxygen at 850 ℃ by adopting 2-step annealing process, which is consisted of the temperature rising step in ambient argon and the temperature maintenance step in ambient oxygen.